dbutilseh.int

delphi控件源码,第三方空间 ,第三方空间

{*******************************************************}
{                                                       }
{                       EhLib v3.6                      }
{       Utilities to sort, filter data in DataSet       }
{                                                       }
{      Copyright (c) 2002-2004 by Dmitry V. Bolshakov   }
{                                                       }
{*******************************************************}

{$I EhLib.Inc}

{$IFDEF EH_LIB_VCL}
unit DbUtilsEh {$IFDEF CIL} platform {$ENDIF};
{$ELSE}
unit QDbUtilsEh;
{$ENDIF}

interface

{$IFDEF EH_LIB_VCL}
uses
{$IFDEF EH_LIB_6} Variants, {$ENDIF}

{$IFDEF CIL}
  EhLibVCLNET,
  System.Runtime.InteropServices, System.Reflection,
{$ELSE}
  EhLibVCL,
{$ENDIF}

  DBGridEh, Db, SysUtils, Classes, TypInfo, Windows;

{$ELSE}
uses
  Variants, QDBGridEh, Db, SysUtils, Classes, TypInfo;
{$ENDIF}

type

  TDateValueToSQLStringProcEh = function(DataSet: TDataSet; Value: Variant): String;

var

  STFilterOperatorsStrMapEh: array[TSTFilterOperatorEh] of String =
  ('', '=', '<>',
    '>', '<', '>=', '<=',
    '~', '!~',
    'In', '!In',
    {=}'Null', {<>}'Null',
    'AND', 'OR',
    '');

const

  STFldTypeMapEh: array[TFieldType] of TSTOperandTypeEh = (
    botNon, botString, botNumber, botNumber, botNumber,
    botBoolean, botNumber, botNumber, botNumber, botDateTime, botDateTime, botDateTime,
    botNon, botNon, botNumber, botNon, botString, botNon, botString,
    botNon, botNon, botNon, botNon, botString, botString,
    botNumber, botNon, botNon, botNon, botNon
{$IFDEF EH_LIB_5}
    ,botNon, botNon, botNon, botNon, botNon, botString
{$ENDIF}
{$IFDEF EH_LIB_6}, botDateTime, botNumber{$ENDIF}
    );

  STFilterOperatorsSQLStrMapEh: array[TSTFilterOperatorEh] of String =
  ('', '=', '<>',
    '>', '<', '>=', '<=',
    'LIKE', 'NOT LIKE',
    'IN', 'NOT IN',
    'IS NULL', 'IS NOT NULL',
    'AND', 'OR',
    '');

procedure InitSTFilterOperatorsStrMap;

{ FilterExpression }

function ParseSTFilterExpressionEh(Exp: String; var FExpression: TSTFilterExpressionEh): Boolean;
procedure ClearSTFilterExpression(var FExpression: TSTFilterExpressionEh);

type
  TOneExpressionFilterStringProcEh = function(O: TSTFilterOperatorEh; v: Variant;
    FieldName: String; DataSet: TDataSet;
    DateValueToSQLStringProc: TDateValueToSQLStringProcEh;
    SupportsLike: Boolean): String;

{ Useful routines to form filter string for dataset }

function GetExpressionAsFilterString(AGrid: TCustomDBGridEh;
  OneExpressionProc: TOneExpressionFilterStringProcEh;
  DateValueToSQLStringProc: TDateValueToSQLStringProcEh;
  UseFieldOrigin: Boolean = False;
  SupportsLocalLike: Boolean = False): String;

function GetOneExpressionAsLocalFilterString(O: TSTFilterOperatorEh;
  v: Variant; FieldName: String; DataSet: TDataSet;
  DateValueToSQLStringProc: TDateValueToSQLStringProcEh;
  SupportsLike: Boolean): String;

function GetOneExpressionAsSQLWhereString(O: TSTFilterOperatorEh; v: Variant;
  FieldName: String; DataSet: TDataSet;
  DateValueToSQLStringProc: TDateValueToSQLStringProcEh; SupportsLike: Boolean): String;

function DateValueToDataBaseSQLString(DataBaseName: String; v: Variant): String;

procedure ApplyFilterSQLBasedDataSet(Grid: TCustomDBGridEh;
  DateValueToSQLString: TDateValueToSQLStringProcEh; IsReopen: Boolean;
  SQLPropName: String);

{ DatasetFeatures }
type

  TDataSetClass = class of TDataSet;

  TDatasetFeaturesEh = class
  private
    FDataSetClass: TDataSetClass;
  public
    constructor Create; virtual;
    function MoveRecords(Sender: TObject; BookmarkList: TStrings; ToRecNo: Longint; CheckOnly: Boolean): Boolean; virtual;
    procedure ApplySorting(Sender: TObject; DataSet: TDataSet; IsReopen: Boolean); virtual;
    procedure ApplyFilter(Sender: TObject; DataSet: TDataSet; IsReopen: Boolean); virtual;
  end;

  TSQLDatasetFeaturesEh = class(TDatasetFeaturesEh)
  private
    FSortUsingFieldName: Boolean;
    FSQLPropName: String;
    FDateValueToSQLString: TDateValueToSQLStringProcEh;
    FSupportsLocalLike: Boolean;
  public
    constructor Create; override;
    procedure ApplySorting(Sender: TObject; DataSet: TDataSet; IsReopen: Boolean); override;
    property SortUsingFieldName: Boolean read FSortUsingFieldName write FSortUsingFieldName;
    procedure ApplyFilter(Sender: TObject; DataSet: TDataSet; IsReopen: Boolean); override;
    property SQLPropName: String read FSQLPropName  write FSQLPropName;
    property DateValueToSQLString: TDateValueToSQLStringProcEh read
      FDateValueToSQLString write FDateValueToSQLString;
    property SupportsLocalLike: Boolean read FSupportsLocalLike write FSupportsLocalLike;
  end;

  TCommandTextDatasetFeaturesEh = class(TSQLDatasetFeaturesEh)
  public
    constructor Create; override;
  end;

  TDatasetFeaturesEhClass = class of TDatasetFeaturesEh;

{ Register/Unregister DatasetFeatures }

procedure RegisterDatasetFeaturesEh(DatasetFeaturesClass: TDatasetFeaturesEhClass;
  DataSetClass: TDataSetClass);
procedure UnregisterDatasetFeaturesEh(DataSetClass: TDataSetClass);
function GetDatasetFeaturesForDataSet(DataSet: TDataSet): TDatasetFeaturesEh;
function GetDatasetFeaturesForDataSetClass(DataSetClass: TClass): TDatasetFeaturesEh;


function IsSQLBasedDataSet(DataSet: TDataSet; var SQL: TStrings): Boolean;
function IsDataSetHaveSQLLikeProp(DataSet: TDataSet; SQLPropName: String; var SQLPropValue: WideString): Boolean;

procedure ApplySortingForSQLBasedDataSet(Grid: TCustomDBGridEh; DataSet: TDataSet;
  UseFieldName: Boolean; IsReopen: Boolean; SQLPropName: String);

var
  SQLFilterMarker: String = '/*FILTER*/';

resourcestring

  // Filter expression operators
  SNotOperatorEh = 'Not';
  SAndOperatorEh = 'AND';
  SOrOperatorEh = 'OR';
  SLikePredicatEh = ''; // 'Like sign' //Use default sign '~'
  SInPredicatEh = 'In';
  SNullConstEh = 'Null';

  // Error message
  SQuoteIsAbsentEh = 'Quote is absent: ';
  SLeftBracketExpectedEh = '''('' expected: ';
  SRightBracketExpectedEh = ''')'' expected: ';
  SErrorInExpressionEh = 'Error in expression: ';
  SUnexpectedExpressionBeforeNullEh = 'Unexpected expression before Null: ';
  SUnexpectedExpressionAfterOperatorEh = 'Unexpected expression after operator: ';
  SIncorrectExpressionEh = 'Incorrect expression: ';
  SUnexpectedANDorOREh = 'Unexpected AND or OR: ';

implementation